I've found that many people have spoken out against having faith itself.
The persuasiveness of their hostility depends, at least in part, on what 'faith' is understood to mean.
At it's most basic, 'faith' means something like 'trust'. And if we poke into it, we'll find that everyone has faith in propositions that they can't prove, whose terms they often can't even define completely. People couldn't live their lives if they didn't.
Of course, if the things trusted on faith turn out to be false, then the faithful one might be more likely to encounter problems. If the faithfully trusted but false beliefs are widespread and somehow harmful, then social problems might arise.
One of my much respected authors, Christopher Hitchens, was notorious for nailing religion to the wall. Dawkins has done so as well. And Sam Harris, though more moderate in his approach, is still known for challenging the ideas of faith.
I think that all three of those authors are atheist polemicists, the militant atheist equivalent of evangelical Christian apologists.
But what is so wrong with faith itself?
Problems can arise if the faith becomes so strong as to be closed-minded, so strong as to exclude the possibility of error entirely. There's a variety of religious rhetoric that praises unshakeable conviction as if it was a virtue. Unfortunately, that can blind the faithful one to the harm that they are doing, putting them in a place where they absolutely refuse to acknowledge it. Think of Christians burning heretics alive in God's name, of communism's gulags and its 'dictatorship of the proletariat', and of Hitler's forceful but blind militancy and his 'final solution'.
Pathologies of faith very definitely exist, and they can become very dangerous.
But it's probably foolish for opposing polemicists to insist that it's somehow "wrong" for people to have trust in anything that hasn't been conclusively justified by facts and logic. I mean, how can the critics justify their own criticisms without calling upon their own intuitive faith that some things are right and other things are wrong?
(There's a strong note of often-unexamined and rarely-justified moralism in a great deal of contemporary cultural-critique.)
I'm not saying that our atheist-polemicists are totally wrong about their criticism of faith. I don't think that they are and agree with a lot of what they say. But perhaps they are a little simplistic and they might be shooting without aiming properly.
I completely understand taking a stand against someone of faith who imposes thier beliefs on others, unwantedly. But I don't understand why people challenge different religions without having been instigated.
There might be some kind of instinctive emotional desire in people to have everyone around them in agreement, to have everyone on the same page. That unanimity would strengthen group solidarity and cohesion in the small paleolithic bands in which human beings evolved. That's my speculation.
This concept has been applied across the board. Christians condemning Muslims, Muslims condemning Christians, Christians condemning Atheists, and Atheists condemning Christians. Of course, condemnation is by no means limited to my provided examples.
Perhaps it's part of being human, part of the ancestral human condition. If my speculation immediately above has any validity, then it might be based on human instincts that had survival value in small hunting-gathering bands, but might have become kind of disfunctional and counter-productive in large civilized societies. For the last 5,500 years, since the rise of the Sumerian city-states, and perhaps since the appearance of settled neolithic villages almost 10,000 years ago, the ability to coexist with people who are different than ourselves has gradually become inescapable, and thus of increasing survival value.
But why is faith in one belief or another, or in any belief, so widely condemned and challenged?
It always seems to be
other people's faith that's being condemned, never our own. These kind of critiques don't seem to be equipped with mirrors.
What does it matter to you if one believes in God, an afterlife, etc, so long as they are not harming or affecting you in any manner?
If you are addressing me with that (I know you weren't, but it's a legitimate question), my answer is that I don't typically care a whole lot about what other people believe. That is, I don't care unless their beliefs start to impact me directly. Then I'll start to care. If they get into my face, or if they try to institutionalize their beliefs in the workings of society itself, eliminating my option to think differently, then I'm likely to become their opponent.
But ultimately, I don't think that I have all the answers about anything. I'm just feeling my way in this lifetime, in this confusing and mysterious place where I find myself. (The universe.) I don't really hold any evangelical doctrines about it, any form of cognitive uniformity that I want to impose on anybody.
For example, I have faith. I'm not Christian, Muslim or Jewish. But I do beleive in a higher power of which I have no knowledge of specifics... hence, "faith". But I don't dare proclaim that I am right or that others are wrong. And I have no reason to impose it upon others. To each their own. But yet I have still been condemned and challenged by non-believers and believers alike as to being 'disillusioned' for having such beliefs.
What is the problem with faith? Why is it NOT okay for one to have beliefs in one's own mind?
Everyone has beliefs. Even the critics of belief have beliefs. If they didn't, they couldn't make their criticisms. Of course, it's also true that not all beliefs are equally true or equally justifiable.
I guess that one lesson from this is that if we are going to claim the freedom to think our own thoughts, then we need to accept the likelihood that many of the people around us are going to be exercising the same freedom. Some of them are probably going to disagree with us. Some might want to argue their case. They might desire very passionately to convince us that they are right and we are wrong. That can turn into an egoistic power-game (one that we see a lot here on Sciforums) which introduces a whole new can-of-worms.
So it's unrealistic for us to expect to be able to progress through our lives without any challenge or disagreement.